(1) Field of the Technology
The present technology relates to an image forming apparatus based on electrophotography, a static recording technique or the like, such as a copier, facsimile machine, printer, so-called multi functional peripheral having these functions or the like, in particular relating to operational control when the image forming apparatus is recovered from a power saving mode such as sleep mode or the like to standby mode for printout operations.
(2) Description of the Prior Art
As the image forming apparatus that acquires image data by receipt from without or by document reading and the like and produces printout of the image data after various image processes, so-called multi functional peripherals (MFPs) having basic functions such as printer, scanner, facsimile and copier functions and also other various functions using network communications have been widely used. Such MFPs are mostly shut down during the night by cutting off the main supply to the apparatus for safety, power-saving and other reasons while they usually have power-saving mode in which the necessary minimum MFP functionality can operate in consideration of FAX reception. This power-saving mode is also called as sleep mode, and is a mode in which functional systems such as fuser, driver and other systems and display of the control portion are turned off or in which power supply to the necessary minimum functional portions as an image forming apparatus, such as an input recognition system for external input lines and particular switches alone is turned on, so as to recover the standby mode when some activating event such as facsimile reception occurs. When the image forming apparatus restores itself into the standby mode for a printing operation from this power saving mode or after an interruption due to some operational trouble of the apparatus and other reasons, there occurs a case in which images to be output are disrupted, needing a control for stabilizing the output images.
As an image forming apparatus that performs image stabilizing control to achieve high quality image forming when recovering from power saving mode to standby mode, there is a known configuration disclosed in patent document 1 (Japanese Patent Application Laid-open Hei 11-160921) in which image stabilizing control is performed when it is necessary while the control is omitted to shorten the waiting time when it is unnecessary. Patent document 1 discloses a density control method in an image forming apparatus that is characterized in that an image density control operation is performed after completion of a warm-up operation that is started when its main power supply is turned on or its sleep mode is cancelled.
On the other hand, patent document 2 (Japanese Patent Application Laid-open 2003-177638) discloses an image forming apparatus in which the density control factors that affect image density are optimized. Specifically, the image forming apparatus is constructed so as to perform one processing mode selectively from a plurality of processing modes having different numbers of steps as the processing modes for optimizing density control factors and it also determines whether a criterion regarding the status change of the apparatus is satisfied or not and performs selectively one processing mode from the plurality of processing modes based on the determined result.
However, in any of the image forming apparatus in accordance with the aforementioned conventional technologies, image quality control mode for obtaining desirable print quality has to be performed after recovery from sleep mode. Accordingly, though the output print quality can be assured, the density control process and/or other operational processes need to be inserted every time of recovery from sleep mode, so that it takes time to obtain the first printout. As a result, for users who do not often perform printing operations, it took a rather long time for image quality control every time the apparatus was recovered from its sleep mode, hence there occurred the problem that the productivity of the printing operation would be markedly degraded.